A mounting device for electronic unit is known that includes a plurality of stages of shelves in each of which a plurality of electronic units, such as printed wiring boards on which a hard disk drive (HDD), a power supply, and an electronic part are mounted, are accommodated in parallel. A duct is provided in a device housing and a cooling fan is provided in the duct. Heat from the electronic units is led to the duct through airflow paths between the electronic units, and then discharged to the outside of the device housing. Japanese Laid-open Patent Publication Nos. 2007-73720 and 11-204974 are examples of related art
Therefore, when the common cooling fan within the device housing is used to uniformly cool each electronic unit, it is desired that a cooling air for each electronic unit does not has a low pressure loss and is uniformed.
However, the plurality of electronic units included in the mounting device for electronic unit are different in height, are different in shape depending on mounted parts, and thus do not necessarily have the same shape. Therefore, when the shape of each electronic unit is different, the pressure loss of the cooling air for each electronic unit is different. In addition, the pressure loss of the cooling air for each electronic unit is different also depending on a manner of arranging the electronic units to the shelf of the mounting device for electronic unit. Therefore, it is desired to control a flow of the cooling air to be constant for each electronic unit.